US7725189B2 - Method, device, and system concerning heart stimulation - Google Patents
Method, device, and system concerning heart stimulation Download PDFInfo
- Publication number
- US7725189B2 US7725189B2 US11/660,771 US66077104A US7725189B2 US 7725189 B2 US7725189 B2 US 7725189B2 US 66077104 A US66077104 A US 66077104A US 7725189 B2 US7725189 B2 US 7725189B2
- Authority
- US
- United States
- Prior art keywords
- signals
- weight vector
- group
- pacing
- electrode
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active, expires
Links
Images
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
- A61N1/00—Electrotherapy; Circuits therefor
- A61N1/18—Applying electric currents by contact electrodes
- A61N1/32—Applying electric currents by contact electrodes alternating or intermittent currents
- A61N1/36—Applying electric currents by contact electrodes alternating or intermittent currents for stimulation
- A61N1/362—Heart stimulators
- A61N1/37—Monitoring; Protecting
- A61N1/371—Capture, i.e. successful stimulation
Definitions
- the present invention relates to heart stimulating devices and systems. In particular to such devices and systems that have the ability to detect evoked responses to stimulation pulses delivered to the heart of a patient.
- the invention also concerns a method of determining a capture verification condition.
- Such devices are able to deliver stimulation pulses to one or more of the different heart chambers: the left ventricle, the left atrium, the right ventricle and the right atrium.
- the devices can often be implanted in a patient.
- the devices are normally also able to sense the electrical activity of the heart.
- the device In connection with such devices, it is known to detect the capture of the heart, i.e. to detect whether the heart actually reacts as intended to a delivered stimulation pulse. If the heart is not captured (i.e. loss of capture) it is possible to arrange the device to deliver a back-up pulse with a higher pulse energy than the first pulse. It is also possible to increase the pulse energy in future stimulation pulses if capture is not detected. In order to save battery it is important that the stimulation pulses are not delivered with an unnecessarily high energy. By varying the energy of the stimulation pulses and by detecting the capture it is possible to find a threshold value for the stimulation pulse energy. Based on the threshold value, a suitable stimulation pulse energy can be determined.
- the detection of capture i.e. the detection of an evoked response (ER) can be done in different manners.
- an IEGM (intracardiac electrogram) signal is detected within a time window (ER window) following a delivered stimulation pulse.
- the determination whether the detected signal indicates a capture can be performed in different manners. It is for example known to use the maximum amplitude of the detected signal within the ER window. It is also known to use a slope or derivative (usually the maximum slope) of the detected signal within the ER window.
- a third known possibility is to detect an area by integrating the detected signal in the ER window.
- the detection of capture involves different problems.
- One problem is the electrode-polarisation.
- the electrode-polarisation is a residual voltage that appears at the electrode used for the stimulation. In particular if the same electrode is used for emitting the stimulation pulse and for sensing the evoked response, the electrode-polarisation can make the detection difficult.
- the delivery of stimulation pulses and the detection of the IEGM can be done either with unipolar or bipolar stimulation and detection.
- U.S. Pat. No. 6,473,650 describes an ER detector.
- the basis for the detection is the idea that the electrode polarisation depends on the stimulation pulse amplitude, while the ER signal does not depend on this amplitude.
- the sensed signal is sampled and the DC level determined before the delivery of the pulse is subtracted from each sample.
- U.S. Pat. No. 5,697,957 describes the suppression of electrode-polarisation components when detecting ER.
- the sensed cardiac signal is added to either a differentiated or autocorrelated sensed cardiac signal and a difference is formed between the original sensed cardiac signal and the autocorrelated or differentiated signal, thereby extracting an ER component from the sensed cardiac signal.
- U.S. Patent Application Publication No. 2003/0083711 describes ER detection by comparing the detected signal with template wave forms.
- the ER is classified as representing a type of capture if the ER waveform highly correlates with a certain template waveform.
- U.S. Patent Application Publication No. 2003/0050671 describes ER detection that involves the correlation between a sensed signal and a template waveform.
- the document describes in particular a method of identifying fusion beats.
- An object of the invention is to provide an improved method of determining a capture verification condition for a heart stimulating system.
- a further object is to provider a method wherein the capture verification condition obtained by the method can be used to distinguish capture from loss of capture with improved accuracy.
- Another object of the invention is to provide an implantable heart stimulating device including such an improved capture verification condition.
- Still another object is to provide a heart stimulating system including such a device.
- the above objects concerning the method are achieved by a method of determining a capture verification condition for a heart stimulating system.
- the heart stimulating system has at least a control circuit, a pacing electrode and a first sensing electrode, the sensing electrode can be the same as or different from pacing electrode.
- the control circuit has a pacing circuit connected to the pacing electrode and sensing circuitry connected to the sensing electrode. The method includes the following steps:
- the pacing electrode positioning the pacing electrode so that the pacing electrode is able to deliver pacing pulses to a heart chamber
- sensing electrode positioning said sensing electrode so that the sensing electrode is able to sense evoked responses in response to pacing pulses delivered by the pacing electrode
- the number of pacing pulses includes pulses which cause the heart chamber to capture and pulses which do not cause the heart chamber to capture
- sensing signals from the sensing electrode within a time window following after each of the delivered pacing pulses and storing the sensed signals in a memory
- the capture verification condition being determined by whether the weighted area, calculated with said particular weight vector, of a sensed signal within said time window, is above or below a certain value.
- the mentioned time window can also be called the ER window.
- This window can start, for example, somewhere between 0 ms and 30 ms after the delivery of a pacing pulse.
- the window can for example have a duration of between 10 ms and 120 ms, preferably between 20 ms and 50 ms.
- weight vector used herein should not be interpreted to literally mean that this concept by necessity must be a vector. However, the concept in question refers to an entity which assigns different weights to different parts of the sensed signal.
- the number of delivered pulses necessary for determining the capture verification condition may vary. However, the number of delivered pulses must be sufficient such that there is a sufficient number of stored signals in each of the mentioned first and second groups. For example, it ought to be at least five or, more preferred, at least ten or, even more preferred, at least 20 stored signals in each of said first and second groups.
- the capture verification condition in this case relates to an area within the time window.
- an area can be obtained by integrating the detected signal within the time window.
- the present invention is based on the insight that in a particular case some parts of the sensed signal within the time window can be more relevant than others for determining whether capture is the case. It has thus been found that by using a particular weight vector which assigns different weights to different parts of the sensed signal, an improved capture detection is obtained. It has also been found that such a particular weight vector can be determined on the basis of the signals stored in said first and second groups. The weight vector is thus chosen such that the signals in the first group is easily distinguished from the signals in the second group.
- the mentioned weighted area is thus preferably an area determined by the sensed signal (for example the integral or negative integral of the sensed signal in said time window) but modified with the different assigned weights in accordance with the weight vector.
- the particular weight vector is determined such that by using the particular weight vector when calculating weighted areas for the stored signals, the signals in the first group are distinguished as much as possible, or at least to a high degree, from the signals in the second group.
- the weight vector can thus be determined such that the distinction between capture and loss of capture for a particular patient is as clear as possible.
- the method includes a Vario test in order to determine a capture threshold, wherein the stored signals are categorised as belonging to said first or second group based on the result of said Vario test.
- the Vario test is known to those skilled in the art. This is a method of determining the capture threshold.
- the Vario test is normally done by causing the pulse generator to automatically step through all possible pulse amplitude settings and by detecting (for example with the help of a surface electrocardiogram) at which amplitude the capture threshold is.
- the determination of said particular weight vector involves an iterative process.
- the iterative process can thereby involve assigning a weight vector and modifying said weight vector iteratively in order to arrive at said particular weight vector.
- By iteratively modifying the weight vector it is possible to arrive at a suitable or optimal weight vector in order to distinguish the signals in the first group from the signals in the second group.
- the determination of said particular weight vector can be done by maximizing, or at least increasing to a sufficient level, a measure of how distinguished the signals in the first group are from the signals in said second group. This can be obtained by using a mathematical optimization method. Several different mathematical optimisation methods are known to those skilled in the art. Examples of such methods will be given below.
- the number of different parts of the signal within said time window, to which weights are assigned is at least 8.
- the first sensing circuit operates with a certain sampling frequency, and the number of different parts of the signal within the time window, to which weights are assigned, thereby corresponds to the sampling frequency.
- control circuit and the first sensing electrode are arranged for unipolar sensing. It should be noted that the invention of course also is applicable to bipolar sensing.
- the mentioned first heart chamber can be an atrium. It is often difficult to detect capture in an atrium. However, with the present invention it has been found that it is possible to determine a capture verification condition that can be used also for detecting capture in an atrium. The invention can of course also be used for detecting capture in a ventricle.
- the heart stimulating system can be an implantable heart stimulating device in which said control circuit is contained, and the calculations performed in order to determine the particular weight vector can be performed in the implantable heart stimulating device.
- the calculations performed in order to determine the particular weight vector can be performed in a non-implantable unit that is separate from the implantable heart stimulating device.
- the mentioned non-implantable unit can be, for example, a so-called programmer that communicates via telemetry with an implanted heart stimulating device.
- An implantable heart stimulating device includes a control circuit that includes:
- a pacing circuit adapted to be connected to a pacing electrode suited to be positioned in or at a heart chamber so as to receive pacing pulses from the pacing circuit such that the pacing circuit is able to pace the heart chamber
- sensing circuit adapted to be connected to a sensing electrode, wherein said sensing electrode can be identical with or not identical with the pacing electrode, suited to be positioned in or at the heart chamber so as to transfer signals to the sensing circuit such that the sensing circuit is able to sense the heart chamber.
- the control circuit is arranged to be able to detect an evoked response to a pacing pulse delivered by the pacing circuit by sensing, with the sensing circuit, within a time window that follows after a pacing pulse delivered by the pacing circuit, wherein a sensed signal is categorized as a capture if one or more capture verification conditions are fulfilled.
- the device operates with at least one capture verification condition which is based on a calculated weighted area within the time window, wherein the weighted area is calculated by using a particular weight vector which assigns different weights for different parts of each sensed signal within said time window.
- An implantable heart stimulating device can thus use a capture verification condition that has been determined according to the method according to the invention.
- the particular weight vector used for calculating the weighted area can therefore be optimized for detecting capture in the particular patient in which the heart stimulating device has been implanted.
- capture can therefore be distinguished from loss of capture with high accuracy.
- the heart stimulating device can for example be used for detecting capture by unipolar sensing in an atrium.
- the implantable heart stimulating device can of course be set up to operate in other manners, for example for bipolar sensing.
- the implantable heart stimulating device can be arranged to detect capture either in an atrium or in a ventricle or in both an atrium and a ventricle.
- the implantable heart stimulating device can also be used in connection with bi-ventricular pacing.
- An implantable heart stimulating system includes:
- first lead is connected to the aforementioned device and the first pacing electrode is arranged on the first lead.
- the system also includes the aforementioned first sensing electrode.
- the system according to the invention has advantages corresponding to those of the heart stimulating device according to the invention.
- FIG. 1 shows schematically a heart stimulating system with a heart stimulating device connected to leads with sensing and pacing electrodes positioned in a heart. The figure also indicates a separate unit.
- FIG. 2 shows schematically an example of a sensed signal within an evoked response window.
- FIG. 3 shows another example of a sensed signal within an evoked response window.
- FIG. 4 shows schematically different areas measured for a number of signals representing captured and non-captured cases.
- FIG. 5 illustrates schematically different weight values of a weight vector for different parts of an evoked response window.
- FIG. 6 shows schematically another example of weight values of a weight vector within the evoked response window.
- FIG. 7 shows schematically a flow chart for a method according to the invention.
- FIG. 8 shows a flow chart of an iterative process that can be used in the method according to the invention.
- FIG. 1 shows schematically an embodiment of a heart stimulating system according to the invention.
- FIG. 1 also schematically shows a heart with a right ventricle RV, a left ventricle LV, a right atrium RA and a left atrium LA.
- the implantable heart stimulating system includes an implantable heart stimulating device 10 according to the invention and a first lead 21 , a second lead 22 and a third lead 23 .
- the implantable heart stimulating device 10 has a casing 12 . Inside the casing 12 a control circuit 14 is located.
- the leads 21 , 22 , 23 are connected to the control circuit 14 via a connector portion 13 of the heart stimulating device 10 .
- On the first lead 21 a first pacing electrode 25 , 26 is arranged.
- the first pacing electrode 25 , 26 is a bipolar electrode is formed by a tip electrode surface 25 and a ring electrode surface 26 .
- the first pacing electrode 25 , 26 can also function as a first sensing electrode 25 , 26 .
- the first pacing and sensing electrode 25 , 26 is located to pace and sense the right atrium RA.
- the second lead 22 has a second pacing and sensing electrode 28 , 29 .
- the second pacing and sensing electrode 28 , 29 is in this case located in the right ventricle RV.
- the third lead 23 has a third pacing and sensing electrode 32 , 33 arranged to pace and sense the left ventricle LV.
- the electrodes are bipolar electrodes.
- unipolar sensing normally the casing 12 of the device 10 functions as a second electrode surface.
- the same electrode functions both for pacing and sensing.
- different electrodes or electrode surfaces
- the control circuit 14 has a first pacing circuit 16 adapted to be connected, via the first lead 21 , to the first pacing electrode 25 , 26 such that the first pacing circuit 16 is able to pace a first heart chamber, i.e. in this case the right atrium RA.
- the control circuit 14 also has first sensing circuit 18 adapted to be connected, via the first lead 21 , to the first sensing electrode 25 , 26 such that the first sensing circuit 18 is able to sense a first heart chamber, in this case the right atrium RA.
- the first sensing circuit 18 is in particular arranged to be able to sense an evoked response ER. Since those skilled in the art knows how such circuits as the pacing circuit 16 and the sensing circuit 18 are designed, these need not be described in more detail.
- the heart stimulating device 10 also includes a memory 19 .
- the control circuit 14 is thus able to detect an evoked response to a pacing pulse delivered by the first pacing circuit 16 by sensing, with the first sensing circuit 18 , within a time window, i.e. the ER window, that follows after the delivery of a pacing pulse.
- the control circuit 14 is also set up to categorize a sensed signal as an indication of a capture if one or more capture verification conditions are fulfilled.
- at least one capture verification condition is based on a calculated weighted area A within the ER window.
- the weighted area A is calculated by using a particular weight vector which assigns different weights for different parts of the sensed signal within the ER window.
- the mentioned capture verification condition is the only capture verification condition which is used in the device 10 .
- this is one of a plurality of conditions used for deciding whether a sensed signal indicates capture.
- the mentioned capture verification condition can thus for example be combined with a slope and/or amplitude detection.
- the device 10 according to the invention does not include any capture verification condition based on templates as in some of the above described documents.
- FIG. 1 also indicates a separate unit 40 .
- This separate unit 40 can be a so-called programmer that can communicate in a wireless manner (so-called telemetry) with an implanted device 10 .
- the separate unit 40 includes a memory 42 .
- the present invention also concerns a method of determining a capture verification condition. Before describing this method in detail, some ideas behind the invention will be described.
- FIG. 2 shows schematically an ER window, marked as a rectangle, and a sensed signal 41 .
- the vertical axis shows the amplitude and the horizontal axis shows the time.
- the signal 41 limits an area A in the ER window.
- the area A can for example be the negative integral of the sensed signal 41 .
- the area A in this case is the area between 0 amplitude and the signal 41 .
- the area A can be used as a capture verification condition. For this discussion, it can be assumed that the signal 41 indicates capture.
- FIG. 3 is similar to FIG. 2 but shows another sensed signal 42 .
- the signal 42 indicates loss of capture.
- the area A in FIG. 3 is smaller than the area A in FIG. 2 .
- the area A can be used as a capture verification condition. However, sometimes it is difficult to distinguish capture from loss of capture by using such an area method. According to the present invention an improved capture verification condition can be determined.
- FIG. 7 shows a schematic flow chart of a method according to the invention.
- a first pacing electrode 25 is positioned such that it is a able to deliver pacing pulses to a first heart chamber, for example to the right atrium RA.
- a first sensing electrode 25 is positioned such that it is able to sense evoked responses in response to pacing pulses delivered by the first pacing electrode 25 .
- the first pacing electrode 25 can be the same as the first sensing electrode 25 .
- the electrodes can preferably be connected to an implantable heart stimulating device 10 as described above. The whole system can thus be implanted in a patient.
- a number of pacing pulses are delivered via said first pacing electrode 25 to the first heart chamber RA.
- the delivery of the pacing pulses can involve a Vario test as described above.
- the delivered pacing pulses thus include both pulses which cause the heart chamber to capture and pulses which do not cause the heart chamber to capture.
- signals from the first sensing electrode 25 is sensed within the ER window.
- the sensed signals are stored in a memory 19 , 42 . Based on the Vario test, the sensed signals can be categorised in a first group and in a second group. The first group represents captured cases and the second group represents non-captured cases.
- a particular weight vector which assigns different weights for different parts of each sensed signal within said ER window is determined.
- the weight vector is to be used for calculating a weighted area within the ER window.
- the particular weight vector can be determined by an iterative process, for example as schematically illustrated in FIG. 7 .
- the selected initial weight vector may for example be a weight vector that assigns the same weight to all the different parts of the signal within the ER window.
- Another example of an initial weight vector that can be used is a weight vector where the weight x i associated with a certain sample (or part of the ER window) i is selected as As ic -As iL , where As ic is the average of the values of sample i for the captured cases, i.e. for the stored signals in the first group, and As iL is the average of the values of sample i for the loss cases, i.e. for the stored signals in the second group.
- the number of different parts of the ER window to which different weights can be assigned can for example correspond to the sampling frequency of the device. If for example the sampling frequency is 512 Hz and if the ER window is 50 ms long, the number of different parts within the ER window is about 25.
- the weighted area for a sensed signal can be calculated as follows.
- a W is the weighted area
- x i is the weight associated with the sample i
- s i is the ith sample
- N is the number of samples in the window (i.e. the number of different parts in the ER window to which different weights can be assigned).
- the weighted areas are calculated for the stored signals with the help of the selected weight vector.
- FIG. 4 shows the areas A calculated with a particular weight vector for the different stored signals, indicated with small circles.
- the horizontal axis indicates the number of different stored signals.
- the first 15 stored signals represent non-captured beats and the following 15 stored signals represent captured beats.
- the first 15 signals are thus the mentioned second group of stored signals and the following 15 signals are the mentioned first group of signals.
- the difference D represents the smallest difference in weighted area between the signals indicating non-capture and the signals indicating capture.
- the difference T indicates the largest difference in weighted area between the signals indicating non-capture and the signals indicating capture.
- the relationship D/T is one possible measure of how distinguished the signals in the first group are from the signals in the second group. However, the relationship D/T is only one example of a measure of distinction. Another example of a measure of distinction is the following:
- M ⁇ A ⁇ ⁇ C - AL SC NC + SL NL ⁇
- the iteration continues by modifying the weight vector. Thereafter weighted areas are calculated for the stored signals with the modified weight vector. The measure of distinction is calculated again. The iteration process continues until a suitable weight vector has been found. The iteration can for example continue until a maximum has been found for the measure of distinction, or until the measure of distinction is sufficient.
- the particular weight vector has now been determined.
- the capture verification condition based on this particular weight vector, is then determined.
- FIG. 7 only very schematically shows an iterative process.
- the iterative process can be any well known suitable mathematical optimization method.
- Rosenbrock's method is Rosenbrock's method.
- Other methods can also be used, such as Powell's method, the Simplex method or a Fibonacci search.
- FIG. 8 shows in some more detail than in FIG. 7 an example of an iterative process that can be used in order to determine the particular weight vector.
- the process of FIG. 8 is a version of Rosenbrock's method applied to the present case. The following symbols are used in FIG. 8 .
- a search direction is initialized. The process is such that all search directions will be searched until a move in any direction would generate a lower value of distinction. Then i is set to be equal to 1.
- f is calculated for a modified w (modified in search direction xi), i.e. f(w+xi*di) is calculated. If the calculated f(w+xi*di)>f(w), then the move to the modified w is considered to be successful. wi is then set to be equal to wi*di and di is set to di*alpha. The process then continues to the next step below in FIG. 8 . If it is not the case that f(w+xi*di)>f(w), then the move is considered to be unsuccessful and the search direction di is changed to di*beta.
- the improvement i.e. the increase in f(w)
- Gamma can be a predetermined small value. If the improvement is under this predetermined value, it is assumed that further iterations will not lead to any significant improvement.
- the particular weight vector is thus determined as the w that is obtained through the iteration.
- the particular weight vector is such that by using the particular weight vector and calculating weighted areas for the stored signals, the signals in the first group are distinguished as much as possible, or at least to a high degree, from the signals in the second group.
- the capture verification condition is thus determined as whether the weighted area, calculated with the particular weight vector that has been found by the iterative process, of a sense signal within an ER window is above or below a certain value.
- FIG. 5 illustrates schematically the weights w of a weight vector for different parts of the ER window.
- FIG. 6 shows schematically the weights of a weight vector that does not assign different weights to different parts of the signal within the ER window.
- the weight of each of the ten parts of the signal within the ER window is thus equal to 0.1 (1/N in the above equation).
- a weight vector of the kind shown in FIG. 6 thus corresponds to the normal integration method according to the prior art that does not assign different weights to different parts of the signal.
- the signals of the first group are thus more easily distinguished from the signals in the second group than if the signals in the first and second groups were distinguished from each other by the area method without assigning different weights to different parts of the sensed signal within the ER window.
- the ratio D/T or M thus increases.
- the calculations necessary in order to determine the particular weight vector is preferably done in a non-implantable unit 40 that is separate from the implantable heart stimulating device 10 .
- the calculations can thus be done in a so-called programmer 40 .
- the capture verification condition can be determined directly after implant of the heart stimulating device 10 in a patient.
- the capture verification condition can be determined when the heart stimulating device 10 has been implanted for a certain time. It is also possible to determine a capture verification condition for an implanted heart stimulating device 10 several times, since it is possible that for example the polarisation conditions for the electrodes 25 , 26 may change over time. It can therefore be beneficial to at a later time determine a new capture verification condition with the method according to the invention in order to optimize the capture verification of the implanted heart stimulating device 10 .
- a heart stimulating device 10 thus uses a particular weight vector for calculating a weighted area in an ER signal.
- the weight vector used in the device 10 is such that the different weights assigned by the weight vector for different parts of the sensed signal within the ER window are optimized for distinguishing capture from loss of capture with the help of the weighted areas.
- the device according to the invention is used for unipolar sensing of an atrium, the device can also be used for sensing any other chamber of the heart and also for bipolar sensing.
Abstract
Description
where AW is the weighted area, xi is the weight associated with the sample i, si is the ith sample and N is the number of samples in the window (i.e. the number of different parts in the ER window to which different weights can be assigned). The weighted areas are calculated for the stored signals with the help of the selected weight vector.
where M is a measure of distinction,
- AC is the average of the calculated weighted areas for the captured beats, i.e. for the mentioned first group,
- AL is the average of the calculated weighted areas for the loss beats, i.e. for the mentioned second group,
- SC is the standard deviation for the calculated weighted areas for the captured beats, i.e. for the mentioned first group,
- NC is the number of capture beats, i.e. the number of stored signals in the first group,
- SL is the standard deviation for the calculated weighted areas for the loss beats, i.e. for the mentioned second group, and
- NL is the number of loss beats, i.e. the number of stored signals in the second group. Approximate levels for AC and AL are shown in
FIG. 4 .
- w is the weight vector (which contains N elements),
- wi is weight number i (the ith element in w),
- x is a set of search directions,
- xi is search direction i,
- di is the step size in search direction i,
- f(w) is a “measure of distinction” (for example D/T or M) for the weight vector w,
- alpha is a constant, wherein alpha>1,
- beta is a constant, wherein −1<beta<0,
- gamma is a constant that implicitly controls the number of iterations.
Claims (28)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PCT/SE2004/001252 WO2006025771A1 (en) | 2004-08-31 | 2004-08-31 | Method, device and system concerning heart stimulation |
Publications (2)
Publication Number | Publication Date |
---|---|
US20070255329A1 US20070255329A1 (en) | 2007-11-01 |
US7725189B2 true US7725189B2 (en) | 2010-05-25 |
Family
ID=36000331
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US11/660,771 Active 2026-05-26 US7725189B2 (en) | 2004-08-31 | 2004-08-31 | Method, device, and system concerning heart stimulation |
Country Status (5)
Country | Link |
---|---|
US (1) | US7725189B2 (en) |
EP (1) | EP1796783B1 (en) |
AT (1) | ATE425790T1 (en) |
DE (1) | DE602004020123D1 (en) |
WO (1) | WO2006025771A1 (en) |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7392088B2 (en) * | 2005-04-28 | 2008-06-24 | Cardiac Pacemakers, Inc. | Capture detection for multi-chamber pacing |
US7593774B2 (en) * | 2006-07-25 | 2009-09-22 | Biotronik Crm Patent Ag | Cardiac pacemaker |
WO2011049875A1 (en) * | 2009-10-22 | 2011-04-28 | Cardiac Pacemakers, Inc. | Apparatus and method for estimating an electrostimulation capture threshold |
US9916431B2 (en) * | 2015-01-15 | 2018-03-13 | Qualcomm Incorporated | Context-based access verification |
US10362948B2 (en) * | 2015-10-23 | 2019-07-30 | Cardiac Pacemakers, Inc. | Multi-vector sensing in cardiac devices with detection combinations |
Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5273049A (en) | 1992-04-09 | 1993-12-28 | Telectronics Pacing Systems, Inc. | Detection of cardiac arrhythmias using template matching by signature analysis |
EP0605244A2 (en) | 1992-12-28 | 1994-07-06 | Cardiac Pacemakers, Inc. | Electrode charge-neutral sensing of evoked ECG |
US5697957A (en) | 1996-08-29 | 1997-12-16 | Pacesetter Ab | Adaptive method and apparatus for extracting an evoked response component from a sensed cardiac signal by suppressing electrode polarization components |
US6473650B1 (en) | 1998-06-16 | 2002-10-29 | St. Jude Medical Ab | Evoked response detector for a heart stimulator |
US20030050671A1 (en) | 2001-09-10 | 2003-03-13 | Kerry Bradley | Method and device for enhanced capture tracking by discrimination of fusion beats |
US20030083711A1 (en) | 2001-10-26 | 2003-05-01 | Yonce David J. | Template-based capture verification for multi-site pacing |
WO2004078258A1 (en) | 2003-02-28 | 2004-09-16 | Medtronic Inc. | Physiological event detection |
-
2004
- 2004-08-31 DE DE602004020123T patent/DE602004020123D1/en active Active
- 2004-08-31 AT AT04775358T patent/ATE425790T1/en not_active IP Right Cessation
- 2004-08-31 EP EP04775358A patent/EP1796783B1/en not_active Not-in-force
- 2004-08-31 US US11/660,771 patent/US7725189B2/en active Active
- 2004-08-31 WO PCT/SE2004/001252 patent/WO2006025771A1/en active Application Filing
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5273049A (en) | 1992-04-09 | 1993-12-28 | Telectronics Pacing Systems, Inc. | Detection of cardiac arrhythmias using template matching by signature analysis |
EP0605244A2 (en) | 1992-12-28 | 1994-07-06 | Cardiac Pacemakers, Inc. | Electrode charge-neutral sensing of evoked ECG |
US5697957A (en) | 1996-08-29 | 1997-12-16 | Pacesetter Ab | Adaptive method and apparatus for extracting an evoked response component from a sensed cardiac signal by suppressing electrode polarization components |
US6473650B1 (en) | 1998-06-16 | 2002-10-29 | St. Jude Medical Ab | Evoked response detector for a heart stimulator |
US20030050671A1 (en) | 2001-09-10 | 2003-03-13 | Kerry Bradley | Method and device for enhanced capture tracking by discrimination of fusion beats |
US20030083711A1 (en) | 2001-10-26 | 2003-05-01 | Yonce David J. | Template-based capture verification for multi-site pacing |
WO2004078258A1 (en) | 2003-02-28 | 2004-09-16 | Medtronic Inc. | Physiological event detection |
Also Published As
Publication number | Publication date |
---|---|
ATE425790T1 (en) | 2009-04-15 |
EP1796783B1 (en) | 2009-03-18 |
US20070255329A1 (en) | 2007-11-01 |
DE602004020123D1 (en) | 2009-04-30 |
WO2006025771A1 (en) | 2006-03-09 |
EP1796783A1 (en) | 2007-06-20 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP0906768B1 (en) | Evoked response detector and a heart stimulator with such a detector | |
US5741312A (en) | Pacemaker system and method with improved capture detection and threshold search | |
EP0941744B1 (en) | Heart stimulator | |
US7426412B1 (en) | Evoked potential and impedance based determination of diaphragmatic stimulation | |
US8428697B2 (en) | “Blurred template” approach for arrhythmia detection | |
JP5833517B2 (en) | Medical system for classifying cardiac responses to pacing pulses | |
EP1007150B1 (en) | Apparatus for tissue stimulation | |
EP0804939A2 (en) | Using MV to classify patient cardiac condition in an implanted device | |
US20090030470A1 (en) | Implantable heart stimulation device with remedial response to anodal capture | |
US4505276A (en) | Device for detecting retrograde conduction | |
EP0952872A1 (en) | Implantable cardiac stimulator with capture detection and impedance based autotuning of capture detection | |
US20110092836A1 (en) | Method and apparatus for determining the coronary sinus vein branch accessed by a coronary sinus lead | |
JPH0566826B2 (en) | ||
CN103987425A (en) | Method for discriminating anodal and cathodal capture | |
US7054688B1 (en) | Heart stimulator with evoked response detector and an arrangement for determining the stimulation threshold | |
US7725189B2 (en) | Method, device, and system concerning heart stimulation | |
EP0786268A1 (en) | Heart stimulator with verification of atrial capture | |
US6501989B1 (en) | Heart stimulator having an evoked response detector | |
US6473650B1 (en) | Evoked response detector for a heart stimulator | |
US6304781B1 (en) | Electrostimulator | |
US8321015B2 (en) | Method and implantable device for selective heart pacing | |
EP1660180B1 (en) | Medical implant for evoked response detection having an adaptive detection time window | |
WO2007081248A1 (en) | An implantable heart stimulating device and method for evoked response detection |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: ST. JUDE MEDICAL AB, SWEDEN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:BJORLING, ANDERS;REEL/FRAME:018981/0138 Effective date: 20070215 Owner name: ST. JUDE MEDICAL AB,SWEDEN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:BJORLING, ANDERS;REEL/FRAME:018981/0138 Effective date: 20070215 |
|
STCF | Information on status: patent grant |
Free format text: PATENTED CASE |
|
FPAY | Fee payment |
Year of fee payment: 4 |
|
MAFP | Maintenance fee payment |
Free format text: PAYMENT OF MAINTENANCE FEE, 8TH YEAR, LARGE ENTITY (ORIGINAL EVENT CODE: M1552) Year of fee payment: 8 |
|
MAFP | Maintenance fee payment |
Free format text: PAYMENT OF MAINTENANCE FEE, 12TH YEAR, LARGE ENTITY (ORIGINAL EVENT CODE: M1553); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY Year of fee payment: 12 |